Hello. I am playing GTA Liberty City Stories and it works good, but often the sound of Radio Songs and Movies Dialogues make very slowdown. It is very annoying. I tried to change Sound Quality in SPU2 Settings, and also i tried to check "Disable Effect Processing" option or change Output Module, but it doesn't helped. Anyone has idea how to fix this?

Audio slowdown is linked directly to the game slowing down. Your CPU is on the slow side for this game, so any time your PC can't keep up everything will slow.

You can try setting the audio plugin to "async" instead of "time stretch", this allows the audio in most games to play full speed regardless of how fast the game is actually playing. This MAY cause glitches in the game though so be warned.